A Little Knowledge is a Dangerous Thing
by vlad the inhaler
Summary: 6th year AU, Harry puts the puzzle together slightly faster. Now he just needs to come up with a plan of action. Fortunately, help comes from an unexpected source. Rated M for a reason. Smut/adult situations.


In a startling moment of clarity, Harry knew.

He knew that Draco was up to something—had known ever since he'd seen him during the end of summer trip to Diagon Alley. Something was going to happen at Hogwarts this year, something terrible, and Draco would be in the thick of it.

He knew, whatever it was, would take place in the Room of Requirements. Draco's smug look of triumph as Umbridge had discovered their club, and now his map's inability to find Malfoy… it couldn't be anywhere but the Room of Requirements.

He knew that without Draco's permission, he would never actually find the room while Draco was in it. He'd tested it himself, furious at the oversight that had allowed their original capture. One only had to ask to be kept hidden, and the room, as always, would provide. Oh, he suspected Dumbledore could have managed to break in, but he very much doubted anyone else would have. He certainly couldn't, and that's what ultimately mattered.

And now, Draco was no longer a member of his house team–a team he'd bribed his way on to begin with. So now, he thought–basking in his certainty–he knew exactly when Malfoy would do whatever it was he was doing. The Slytherin-Gryffindor match was in two weeks, and the hotly-contested rivalry meant everyone else in the school would be watching the game.

The warm glow of being three steps ahead of his opponent collapsed a moment later, when he realized how impotent he was to capitalize on this discovery. Ron and Hermione, bless them, were still convinced that Malfoy was nothing more than his nasty annoying self, a thorn in the side, perhaps, but hardly one that demanded particular attention. And to go to a professor… He grimaced at the idea, remembering the rebuttals he'd received from them year after year. He could go to Dumbledore… but Snape would cover for Malfoy, and without proof, his allegations would not be taken seriously.

_I don't need to stop him_, Harry thought to himself, _I just need proof. One step at a time._

That still left him painfully blank as to how to get out of the quidditch match.

"Harry? You all right, mate?" Ron's voice called out, and roused Harry from his Charms-essay-induced stupor.

"Yeah, thanks. Just out of ideas to write about, really," he replied morosely.

Ron snorted. "Caterwauling charms. They are often loud. In conclusion, noisy."

Harry snickered, which earned both of them a glare from Hermione.

"Anyway," Harry said, stretching his arms a bit, "I'm think I'm going to go out for a bit of a stroll. You lot want to come along?"

Hermione shook her head and muttered something about Restoration Potions and Inter-Mineral Transfiguration.

Harry shrugged and turned to Ron, who seemed torn between going with him and staying where he was. At long last, he gave Harry a pitying look.

"McGonagall says that if I don't keep my grades up, she'll boot me from the team, cup or no," he replied. "I never thought I'd regret the twins not being here, but she seems to have a lot more time to get onto the rest of us."

Harry nodded. He empathized; McGonagall had been coming down hard on him, too, since Fred and George had left.

"Right, then. I'll see you all in a bit," Harry said in a faux-jovial voice. He made his way out of the common room, and then out the castle entirely. He walked towards the lake to take advantage of the last vestiges of evening light that splashed over it.

Halloween had passed now, and so far north in Scotland, the sun fell rapidly, and night-time greedily overtook the world. As he trudged along toward the lake, he sighed at the thought that winter would be so quickly upon them. He knew every student lined their robes with warming charms in the winter months, but it didn't seem to stop the chill. Idly, he wondered if the teachers deliberately made it colder. Character building and all that rot, he thought uncharitably.

He was brought out of his musings by screams of laughter coming from the sloping grounds between the lake and the castle. He walked towards it, for lack of a better purpose. Once the shrieking individuals finally came into his vision, he couldn't help but smile; a number of younger years were flying on broomsticks, under the watchful eye of Professor Flitwick.

"Hello, sir," Harry called out respectfully, as he moved next to the diminutive professor.

"Ah, Harry! Good to see you," Flitwick responded cheerfully. "Lovely evening to be out, isn't it? Surprised you're not up there with them." He chuckled heartily.

Harry gave him a small, awkward smile in return. Nothing more was said while they watched the fliers perform acrobatics in the sky. After what seemed like a short time, but what Harry suspected was actually much longer, Flitwick touched his wand to his throat, and called them all down with an amplified voice. The last few rays of the sun had just disappeared, and Harry prepared to leave, and to let the professor get on with his charges.

"Harry… Harry Potter, is that you?" a girly voice shrieked out, causing a titter of giggles from the group.

Harry winced. He could tell where this was going, and looked to Flitwick for support.

The professor, to Harry's chagrin, only smiled knowingly and shrugged his shoulder.

"Harry, it is you! Were you watching us? How were we?—not that we're anything like you on a broom, I'm sure," gushed the dark-haired girl who was all of a sudden clinging to his arm. She looked familiar, and he could just make out the crimson trim that marked her as belonging to his house, but otherwise he had no idea…

And then he recalled her. A frown sprang unbidden to his face at the memory of their introduction.

"Vane, isn't it?"

She beamed at him. "You can call me Romilda, Harry."

"Right then," he said, and he turn awkwardly to go. Suddenly, he regretted making this venture out of the castle. Still, she clung to his arm, and locked into step beside him. He squirmed awkwardly at the thought of the looks on his friends' faces if he came into the Common Room with a star-struck fourth year on his arm. Oddly enough, the thought of Katie Bell flashed through his mind.

Romilda was oblivious, and prattled on about things he didn't care about in the slightest.

"I thought about trying out for the house team, of course," she continued, though he had no idea what she had said already. "But well… you were already a seeker, and I'm not really fond of being a Chaser."

Harry had to chuckled at that.

And then it hit him. The final puzzle piece.

"A seeker?" he asked, with some effort to inject interest into his voice.

"Yes," she replied, equal parts flirtatious and demure. "I'm not bad on a broom you know," she said, and Harry was once more at a loss.

He shook his head to clear his thoughts. "Well…" he said, as he tried his best to sound undecided about the whole thing. "You did look pretty good up there, while I was watching," he lied. Frankly, he had no idea which of the gaggle she had been.

She took no notice, but stared up up at him instead. Her big brown eyes were wide with admiration.

"I was thinking… You know, I get knocked around a bit, and I've only got two more years. I was thinking about looking for a replacement."

She gasped, and looked ready to squeal.

"It'll have to be hush-hush," he whispered conspiratorially.

She clamped her mouth shut, and nodded eagerly.

"It's house strategy, see. We don't want to let them know what's going on, or they'll be ready for you." He felt a twinge of guilt; he didn't know this girl, but he couldn't help but feel she didn't deserve to be used as such. Still, Malfoy had to be stopped. "Why don't you meet me tomorrow after class at the pitch, and I'll give you a few pointers?"

At this point, Harry expected her to laugh at him, to see through his thinly veiled motives and mock his stupidity. Instead, she gasped, and her hands tightened around his arm as she moved even closer to him. He shuddered, and increased the distance between them to a half step.

"Do you mean it, Harry?" she whispered.

Harry nodded, and she practically bounced in excitement. "I won't let you down, Harry–I'll be there; I won't tell anyone." She looked around, as if expecting the student body in its entirety to jump out from around the corner. "I have a secret date with Harry Potter," she said to herself gleefully. Harry shuddered a second time.

"I have to go talk to McGonagall now then—before she leaves her office—about getting some time on the pitch." He was lying, but whether she detected it, she began to pout.

She nodded, though, her expression ever trusting, before she detached herself from him, and flounced up the stairs towards the Gryffindor Common Room. He sighed in vain hope that she wouldn't gossip. The cover story was decent enough if she did squeal, though no doubt he'd earn an earful from Hermione or Ginny. He turned right, not towards McGonagall's office, but toward Slughorn's. On to stage two.

Romilda, he was thrilled to discover the next day, was, in fact, a fairly decent flier. If not for her obsession with him (and her rather active imagination in regards to the former), he would have happily put her on the team as a reserve. Now, he longed for the day of the match, if only to escape from what Romilda had begun calling their 'forbidden romance'. The only positive to come from her almost zealous infatuation with him was that she had told no one about his plan—at least as far as he could tell, at any rate.

Finally, the day came, and Harry ushered the team quickly through the locker rooms. He sent them into the waiting hall just beside the pitch, and told them he needed a moment alone. Despite looks amongst themselves, the team collectively nodded.

"Romilda, you can come out now," Harry hissed towards the showers. The witch came out, a-buzz with energy.

"What is it, Harry? This is ever so exciting, us here, them outside, perhaps to return at any moment and discover our secret love! Is that your plan—to seduce me here and now, before you vanquish your opponents?"

"My…" Harry paused, horrified. He'd grown somewhat accustomed to her creative interpretations of reality, but she'd never been so brazen. "Not quite," he mumbled, in an attempt to restore some sanity to the situation. "I need you to drink this." He pulled out a pale cream potion in a glass bottle that he'd recently liberated from Horace Slughorn's classroom.

She looked at it, and nodded at last. "So this is how it must be. Very well, my love, but promise you shall hold me tenderly to you in our last moments on this wretched earth. Promise me you'll wait for me in heaven if you should die first."

"Oh, for—" Harry paused to bite back a rude comment. "It's Polyjuice, all right? You're going to be me. I have to do something very important, something nobody can know about, and now is the only time. I… you're the only one I trust, Romilda," he said, and finished his semi-prepared remarks.

"I'm… going to be you?" Romilda stuttered. It took a second, but her face lit up in overwhelming joy as she realized what was happening. "Anything for you, Harry! Oh, thank you! I won't let you down! To be entrusted with your body, your soul…!"

At that moment, Harry realized that by looking at the big picture, he had not come to fully appreciate just how bad an idea this was in the details. He was taking a witch with an already unhealthy view of him, and give her complete control of his body. He really should have thought of a better plan—smuggling one of the twins into the school and dousing them up would have been easier than this, surely…

But it was too late. Harry nodded to her, and handed her the vial. "It only lasts for an hour on ingestion, but there is some time for overlap. Take a drink now, then make sure to drink from my water bottle outside; the whole thing's been laced with Polyjuice as well, though you'll need to add a hair to it, since I couldn't risk one of those lot drinking from it first." He winced slightly as he plucked a hair from his own head. "You've got to end the game within the hour, or we're sunk, you understand?"

She nodded vigorously.

In truth, Harry was less concerned about this than anything else. Once he had his proof, everything else would be easy enough to get out of. They wouldn't punish him if he revealed a threat to the school. Not _much_, anyway.

He hadn't expect Romilda to undress right then and there in front of him, and give him a come-hither grin the entire time, though in retrospect, he really should have. Nor had he expected her to drink the potion before putting on his Quidditch robes. As he slunk away, he considered asking Hermione about the Oblivation Charm. While the memory of an admittedly attractive girl prancing about naked was appealing, the part where she'd suddenly sprouted a penis–his penis, at that–was anything but.

He had never found the school so empty.

He'd been out a number of times past curfew and had wandered the halls alone, but then there had always been that sense of taboo, an odd rightness in the fact that nobody was about. Now though, the halls were empty by choice. He sat in a corridor and watched the remnants of the students trickle down towards the pitch. Only eight had stayed inside: three witches had remained behind in the library, and a cluster of three Hufflepuffs he did not know had congregated in their common room, but for all intents and purposes, the school itself was abandoned.

Harry smirked. The name 'Draco Malfoy' had turned around, and was heading towards the northwest atrium that was the shortest route to the Room of Requirements. Minutes later, Draco passed his hiding spot, and Harry followed, covered in his invisibility cloak as Malfoy continued on, completely unaware he was being followed.

As he expected, Malfoy made his way to the Room. He paced three times, before the door appeared and opened wide. Quickly, Harry scooted as close to Malfoy as he dared, and slid in behind him as the door began to close on its own accord. The blond twit noticed nothing; his concentration was focused on a beat-up old cabinet in front of him.

"How to fix it…?" he mumbled to himself.

Harry looked around the room. He noticed all sort of odds and ends that didn't seem to fit. Broken fanged Frisbees, ripped and yellowed books, dungbombs scattered across the floor, and other things too–a large statue of a vampire missing both arms, a number of grayed and empty portraits, and an enormous chandelier were among the more obvious pieces in the room.

And of course, there was the plain—if dented—cabinet Malfoy was staring at.

"How to fix it…?" he asked himself again.

And once more, Harry knew.

Fred and George had knocked one of the Slytherins into this cabinet; they'd bragged about it to Harry for weeks after the boy was finally rediscovered. A vanishing cabinet. Mrs. Weasley had talked about installing one in the Burrow, before she'd been dissuaded of the idea. If Malfoy could fix it… but this, this wasn't proof enough, not yet. Dammit, but he needed something. He froze, imagining a scenario where Romilda was caught, he was outed… and absolutely nothing came of it. Dammit, he knew what Draco was up to! It could not end like this!

And then, as if his prayers had been answered, Draco turned around. He drew his wand and aimed it a few feet to Harry's left. "Who's there?" he shouted, panicked. "Who are you? Aguamenti!"

Harry was forced to admire Draco's spell-choice. The spell was harmless, and was not in itself incriminating. Yet Draco slung the water in a wide arc, and Harry could not hope to dodge. Furiously, he scrambled for his wand, all the while cursing himself for being so unprepared for a change in plans.

"Finite Incantatum," Draco spat, his wand aimed directly at Harry. When nothing happened, Draco's face turned a violent shade of red. "Potter! Accio Cloak."

Harry tried to move to his right while raising a shield, but the cloak sailed off, and landed at Malfoy's feet. His face was enraged, furious at the discovery, and he turned on to Harry hatefully. "How dare you… How dare you, Potter!" The madness crept into his eyes, and Harry waited—he needed to wait, to let Malfoy fire the first shot. He needed proof, even at the risk of letting Malfoy get the first shot of their duel.

And in his madness, Malfoy delivered.

"Avada Kedavra!"

Harry stepped nimbly, and avoided the curse easily.

Malfoy's eyes widened; his already gaunt face paled even more. There was no return. In two seconds, he had condemned himself forever.

Harry had witnessed many expressions from Draco before, but he had never witnessed such hopelessness.

And inside, a part of Harry smiled.

"Expelliarmus!" Harry shouted, aware of his lack of true dueling spells and eager to end the fight quickly. "Reducto!"

The latter spell flew over Malfoy's shoulder and slammed into the precious vanishing cabinet. The curse on Malfoy's lips died as he saw the destruction of an admittedly impossible hope nonetheless reduced to rubble.

It was anticlimactic, but Harry wasn't inclined to demand a rematch. Malfoy, now sunk with despair, did nothing as Harry threw the disarmament charm once more. Malfoy's wand lifted from his hand and skittered across the floor. A moment later, the boy was stunned, and had fallen face-first into the remnants of the cabinet.

Harry didn't leave the Room of Requirements for a long time.

He'd checked the map with a quarter of an hour to spare, relieved to find the crowd dispersing and heading into the castle. The Quidditch teams were retiring momentarily back to the locker room, where Romilda would be able to drink once more. He had no idea which team had won, but at that moment he simply didn't care.

Malfoy was going to Azkaban.

He should have felt relieved at that. There was no doubt that his rival would kill if given the chance–he'd already proven that. But he knew, more than most wizards and witches did, what Azkaban could do to a person. He had, he supposed, indirectly sent a number of Death Eaters to the prison, but even that didn't feel like what he was about to do. They deserved it, had escaped only to continue their murderous ways, and had brought it down about themselves. Malfoy…

There was no question he deserved what was coming, but that didn't fill Harry with joy. Instead he sat there for two more hours and watched the frozen body of Malfoy stare up at him, though the eyes were dull and unfocused. His life, he reflected, was never simple, but he would not let Malfoy's choices burden him any longer. Resolved, he left the room, ready to report to Dumbledore what had transpired.

And instead, he ran straight into Seamus and Dean.

"There he is, man of the hour!" bellowed Dean, utterly at ease despite the three crates of butterbeer levitating beside him.

"We wondered where you got to. Thought you were off in a little private celebration!" Seamus continued, and he winked at Harry.

_Settles who won then_, Harry thought, and returned to the conversation.

"Err… have I been gone long, then?" Harry asked, in a fruitless effort to act non-chalant.

Seamus gave him a funny look. "You said you were going to the bathroom an hour ago."

Dean went on, "Um… well, that is to say we heard noises and thought it best to leave well enough alone."

Harry looked aghast. "I was… Was I… What did you hear?"

His two dorm-mates shared a look, then turned back to Harry. "We won't say a word to anyone, honest," Seamus replied. "And we didn't hear anything… much. Just kept moaning 'Romilda.' Got back to the room, and after a check, found out she wasn't around either. Didn't take much to put two and two together."

Harry turned a paler shade of white.

"Nobody else knows," Dean reassured. "The pair of us were sent out to make a run to the kitchens, and I was just going to check and see if the coast to the Astronomy Tower was clear. Lavender…" he said with a shrug, as if that explained everything.

"Thanks, guys, and please, _please_ don't talk to anyone about this. I'll be right back." With that, Harry bolted toward the Prefects' bathroom, leaving two smirking boys in his wake.

When he got there, Harry opened the door, horrified at the thought of what he might find there. His first reaction was one of relief. There was only one person inside. Whatever had happened, it hadn't happened with somebody else as well.

Then he choked. Lying next to the bath on an enormous fluffy pink pillow, painfully erect, was himself, and he was jerking himself off forcefully. He reflexively covered himself at just how jarring his strokes were.

This, too, was being Oblivated at the soonest opportunity.

Then he moaned.

"Yes, Romilda, love of my life, more. More. Take me into your maiden folds, let me become one with you, flesh and soul. Oh, my sweet! Deeper, Romilda, deeper. My sweet flower, my soul mate. I'll never leave you, oh!"

There was no question this was the most fucked up thing he'd ever seen.

"What?" He couldn't finish his thought. "_What_?!"

"Harry!" Romilda-Harry yelped, suddenly brought out of her fantasy by his presence.

Both Harrys stared at one another, totally lost for words.

"Stupefy!"

The haziness that accompanied the Ennervation Charm was still thick in his head as he awoke. He shook it to try and clear it; his long hair danced across his ears and tickled his bare shoulders as he did so.

… That wasn't right.

He opened his eyes and looked into the mirror, confused, as his hair was normally not a problem. He tried to get up, to ignore the disconcerting look on his own face as he pushed himself upward.

The mirror pushed back.

"I love you Romilda," his reflection cooed. "I'll be with you forever, I swear it." His hand brushed softly against his cheek. Harry flinched, and tried to back away from his suddenly very real reflection.

And then as he remembered, a high-pitched yelp came from his throat.

A throat, that like the hair, was not his.

"You didn't" he whispered, fearful.

"Don't worry, my sweet. It will only hurt for a moment, and then there will be eternal bliss as our soul-bond emerges and we become one."

"No," Harry whimpered.

Harry—no, Romilda—pushed him backwards, and though he tried to resist, her body was not strong enough to avoid Harry-Romilda's force.

"The Polyjuice potion… You didn't use it all. You took some out!" Harry finished, horrified.

All the pieces came together. Harry knew.

"I'm so sorry, Romilda my angel, the girl of my dreams," Romilda whispered into his ear, nibbling slightly on his (her?) earlobe as she did so. "But this is how it must be. Lapsus Stellarum!"

Harry heard the charm, but it took him a moment to recognize it as a medical charm to relax muscles. He fell limply, like a rag doll. He stared up at Romilda out of the corner of his eye. He felt a surreal detachment as he knew what was coming next.

"I love you, Romilda," Romilda whispered once more, staring him straight in the eyes. "And I know you love me too."

And then, Romilda plunged.


End file.
